Email API benchmarks

Knock built customer engagement infrastructure that powers notifications for product-led companies—and then they dropped something that makes the entire email industry look like a guessing game. They just launched Email API Benchmarks, a real-time dashboard showing exactly how the top email providers stack up. We're talking response times, error rates, delivery speed, and growth metrics for 10 providers, updated daily, powered by data from billions of messages sent through their platform. That's not a survey. That's not a poll. That's real performance data from actual traffic.

The numbers are brutal. SendGrid dominates with 500M+ messages and a 22ms median response time—literally untouchable. Resend is the fastest grower at #1 despite handling 10M-25M messages, probably because their 79ms response time is 3x faster than Mailgun's. Meanwhile Sparkpost is out here with a 287ms response time and a 0.21% error rate, which is basically a participation trophy. Amazon SES sits at #3 with 145ms and 0.00% errors—solid but not winning any speed contests. If you're building product and choosing an email provider based on vibes, this dashboard just became your new bible.

This is what happens when you have scale. Knock didn't just decide to publish benchmarks—they literally have the data because billions of messages flow through their infrastructure. The arrogance of publishing your competitors' performance metrics when you're the one with the traffic? That's the kind of move that makes you wonder what else they're cooking.